1. Field of the Invention
This invention relates generally to telecommunications, and, more particularly, to wireless communications.
2. Description of the Related Art
In the field of wireless telecommunications, such as cellular telephony, a system typically includes a plurality of base stations (or NodeBs in 3GPP (3rd Generation Partnership Project) terminology) distributed within an area to be serviced by the system. Various mobile devices (or User Equipment-UE in 3GPP terminology) within the area may then access the system and, thus, other interconnected telecommunications systems, via one or more of the base stations. Typically, a mobile device maintains communications with the system as it passes through an area by communicating with one or more base stations, as the mobile device moves. The process of moving among base stations is commonly referred to as a soft handoff and it may occur relatively often if the mobile device is moving rapidly. The mobile device may communicate with the closest base station, the base stations with the strongest signal, the base stations with a capacity sufficient to accept communications, etc.
To allow a mobile device to periodically communicate with these other base stations, a wireless system, such as UMTS (Universal Mobile Telecommunications System), allows for gaps to periodically occur where the mobile device is not required to communicate with its current serving base station, but instead use the gap to monitor other base stations to which it may subsequently desire to handoff. Typically, for a small transmission time interval (such as 2 ms (millisecond) data packets in 3GPP-UMTS), when a transmission overlaps with the transmission gap, the entire transmission for that 2 ms packet is cancelled regardless how much the overlap is. Typically, any overlap between a scheduled transmission and the transmission gap will result in the transmission of the slots or frames (if the frame is 2 ms in duration) being cancelled (DTXed). However, canceled transmissions can create significant inefficiencies in wireless systems, such as 3rd Generation Partnership Project (3GPP) systems. For example, in the event that a relatively minor overlap with the specified transmission gap occurs, such as a single chip overlap, the entire transmission, such as an entire slot or the 2 ms frame, may be cancelled, even though the slot may be transmitted without negatively affecting communications between the mobile devices and the non-serving base stations during the transmission gap.